West Nile virus at highest level ever in California mosquitoes

West Nile virus has escalated across California, with more mosquitoes impacted than ever before and an increase in the number of residents who have contracted the potentially fatal disease, state health officials said Wednesday.

"The proportion of mosquitoes infected with West Nile virus is at the highest level ever detected in California," said Dr. Ron Chapman, director of the California Department of Public Health, in a statement. "Last week, 52 new human cases were reported to the CDPH. We expect to see more people become infected as this is the time of year when the risk of infection is the highest."

There has been a 34 percent increase in the number of infected mosquito pools this year, compared with the same time last year, according to state data.

So far, there have been 181 reported human cases, a 79 percent increase over the same time last year. Eight confirmed deaths have been reported to state health officials.

Vector control officials have said West Nile tends to pick up pace during drought years, because while there are fewer sources of standing water, pools are more likely to be stagnant longer.

West Nile virus is transmitted to humans and animals by the bite of an infected mosquito, health officials said. Flu-like symptoms can occur, and while most people have a low risk of serious illness, about 1 percent of those infected can develop serious neurologic illness. People who are 50 and over or who have pre-existing medical conditions such as diabetes and/or high blood pressure have the greatest risk of developing complications.

Chapman reminded Californians to remain vigilant by remembering the three D's:

• DEET: Use it as insect repellent.

• DAWN AND DUSK: Mosquitoes bite in the early morning and evening.

• DRAIN: Eliminate all sources of standing water on your property, because that's where mosquitoes breed.